This dataset contains 48 U-Th ages of 14 speleothems used to reconstruct past sea level between 9ka and 421ka ago. They were collected from submerged caves in an area (<20 km) around Tulum, Quintana Roo, Mexico (20.2°N, 87.5°W) at elevations between 0.0 m a.s.l and -28.7 m a.s.l. The speleothems were collected in situ and their elevation was measured with a dive computer (+-0.1m) at the base of the speleothem. Speleothem length ranges between 2 cm and 34 cm. The measurements were carried out by a multi-collector inductively coupled plasma mass spectrometer (ThermoFisher Neptune Plus).

Errors are 2 sigma analytical errors (absolute uncertainties). All calculations used the decay constants of Cheng et al. (2013) for 234U and 230Th, Jaffey et al. (1971) for 238U and Le Roux and Glendenin (1963) for 232Th. Corrected 230Th-U ages assume an initial 230Th/232Th activity ratio of 3.5 ± 1.3. Ages are given as age before the year 1950 CE. Measurements were carried out at University of Heidelberg (Germany) in the years 2018/2019 CE.